1. Field of the Invention
The present invention relates to an optical film and more particularly to an anti-reflection film, a coating composition, a polarizing plate and an image display device.
2. Description of the Related Art
In recent years, display devices have been more used at home. Thus, these display devices have been required to have sufficient toughness against handling by ordinary users. The optical film to be provided on the surface of various image display devices such as liquid crystal display device (LCD), plasma display panel (PDP), electroluminescence display (ELD), cathode ray tube (CRT) and SED (Surface-Conduction Electron-emitter Display) is required to have a high physical strength (e.g., scratch resistance), transparency, chemical resistance and weathering resistance (e.g., moist heat resistance, light-resistance). Further, in order to prevent the drop of contrast by the reflection of external light or image, anti-glare properties or anti-reflection properties are required. Further, a countermeasure for preventing the attachment of dust deteriorating the viewability of display to the surface of the optical film is required.
From the standpoint of prevention of the attachment of stain, it is effective to lower the surface free energy of the optical film. To this end, a fluorine-containing stain inhibitor is disclosed (see, e.g., JP-A-9-127305).
On the other hand, it is known to provide an antistatic layer containing an electrically-conductive particulate material from the standpoint of prevention of attachment of dust (see, e.g., JP-A-2005-196122).
From the standpoint of reduction of the refractive index of electrically-conductive particulate material, a particulate silica the surface of which is coated with antimony oxide is proposed (see, e.g., JP-A-2005-119909).